<script>
  var a = b = c = 8;          // 为三个变量同时赋值
</script>

<script>
  var num1 = 2, num2 = '2';
  num1 += 3;
  num2 += 3;
  console.log(num1, num2);   // 输出结果为：5 "23" 
</script>